Generally, container bodies to contain therein foods are made of materials, such as synthetic resin, heat resistant glass, heat resistant ceramic material and etc. Particularly, container products made of synthetic resin are easily adapted for mass production to reduce production costs thereof, and can be easily handled. Thus, the container products made of synthetic resin have been widely used.
The conventional containers include locking units which are provided on each of both the container bodies and covers to stably preserve and store therein foods and to prevent the foods from undesirably leaking out.
In the conventional containers, the container bodies each include a plurality of locking projections which are projected outward from predetermined portions around a circumferential outer surface of each of the container bodies at predetermined intervals. The cover of the containers includes a plurality of locking flaps which are provided to be vertically rotated around a film hinge. Each of the plurality of locking flaps has a coupling hole to lock each of the locking flaps to each of the locking projections.
To couple the cover to a container body, the cover is placed on an open top of the container body. In the above state, the plurality of locking flaps of the cover are rotated and pressed toward the container body, so that each of the locking flaps is elastically hooked to each of the locking projections of the container body while each of the locking projections is inserted into the coupling hole of each of the locking flaps.
However, the above-mentioned conventional containers have several problems as follows.
First, the conventional container is problematic in that it is impossible to stack. Recently, according to the trend of people eating fewer meals at home, and the trend of toward smaller families, when foods are prepared or cooked at home, most people do not cook a lot of food at a time. However, there are frequent occasions when a variety of foods are cooked a little at a time. As such, when various kinds of foods are required to be contained in a container, it is better to use a plurality of container bodies than to increase the size of one container body. However, the plurality of container bodies occupy a lot of space in a refrigerator. To solve the above problems, a multi-layered container, in which a plurality of container bodies are stacked while using one cover, is required.
However, in case that the plurality of container bodies are stacked, an outer surface of a bottom of each of the container bodies may be smeared with foods which are contained in a lower-layered container body. Furthermore, when one of the container bodies, smeared with foods on the outer surface of the bottom thereof, is put down on a surface on which dust is deposited, the dust may adhere to the outer surface of the bottom of the container body. Thereafter, when the container body smeared with the dust is again layered on another container body, the dust may fall onto foods which are contained in the another container body.
To prevent the above-mentioned unhealthful situation, a means for preventing the foods from being smeared on an upper-layered container body must be proposed.
In the meantime, to provide the conventional multi-layered container, new container bodies must be specifically designed and produced. Therefore, existing container bodies cannot be used in the conventional multi-layered containers. To overcome the above-mentioned problems, a new means must be developed to allow for use of existing container bodies in the conventional multi-layered container, thus reducing household expenses.